U.S. patent application number 11/077385 was filed with the patent office on 2005-10-13 for vibrating plate for speaker and method of fabricating the same.
This patent application is currently assigned to PIONEER CORPORATION. Invention is credited to Kasahara, Yuichi, Tomiyama, Hiroyuki.
Application Number | 20050226459 11/077385 |
Document ID | / |
Family ID | 35060592 |
Filed Date | 2005-10-13 |
United States Patent
Application |
20050226459 |
Kind Code |
A1 |
Tomiyama, Hiroyuki ; et
al. |
October 13, 2005 |
Vibrating plate for speaker and method of fabricating the same
Abstract
A vibrating plate for a speaker, includes: a magnesium vibrating
plate whose major component is magnesium; and an edge comprising a
resin in which an inner peripheral edge of the edge is bonded to an
outer peripheral edge of the magnesium vibrating plate for
attaching the magnesium vibrating plate to a frame, in which the
inner peripheral edge of the edge is constituted by a structure
having a pinching groove which the outer peripheral edge of the
magnesium vibrating plate is brought into close contact with and
fitted to, and the edge is formed integrally with the magnesium
vibrating plate by insert molding.
Inventors: |
Tomiyama, Hiroyuki;
(Yamagata, JP) ; Kasahara, Yuichi; (Yamagata,
JP) |
Correspondence
Address: |
SUGHRUE MION, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
SUITE 800
WASHINGTON
DC
20037
US
|
Assignee: |
PIONEER CORPORATION
TOHOKU PIONEER CORPORATION
|
Family ID: |
35060592 |
Appl. No.: |
11/077385 |
Filed: |
March 11, 2005 |
Current U.S.
Class: |
381/424 ;
381/398 |
Current CPC
Class: |
H04R 7/18 20130101; H04R
2307/204 20130101; H04R 2307/027 20130101 |
Class at
Publication: |
381/424 ;
381/398 |
International
Class: |
H04R 025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 12, 2004 |
JP |
P2004-069993 |
Claims
What is claimed is:
1. A vibrating plate for a speaker, comprising: a magnesium
vibrating plate whose major component is magnesium; and an edge
comprising a resin in which an inner peripheral edge of the edge is
bonded to an outer peripheral edge of the magnesium vibrating plate
for attaching the magnesium vibrating plate to a frame, wherein the
inner peripheral edge of the edge is constituted by a structure
having a pinching groove which the outer peripheral edge of the
magnesium vibrating plate is brought into close contact with and
fitted to, and the edge is formed integrally with the magnesium
vibrating plate by insert molding.
2. A method for fabricating a vibrating plate for a speaker
including a magnesium vibrating plate whose major component is
magnesium; and an edge comprising a resin in which an inner
peripheral edge of the edge is bonded to an outer peripheral edge
of the magnesium vibrating plate for attaching the magnesium
vibrating plate to a frame, comprising: forming the edge integrally
with the magnesium vibrating plate by insert molding, wherein the
inner peripheral edge of the edge is constituted by a structure
having a pinching groove which the outer peripheral edge of the
magnesium vibrating plate is brought into close contact with and
fitted to.
3. The method according to claim 2, wherein the magnesium vibrating
plate is delivered to a place of the insert molding of the edge
after cutting an outer periphery of the magnesium vibrating plate
to a predetermined dimension and in a state of not subjecting a cut
face of the outer periphery of the magnesium vibrating plate to an
end face treatment for rust proofing.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a vibrating plate for a
speaker using a magnesium vibrating plate and a method of
fabricating the same.
[0003] 2. Description of the Related Art
[0004] According to a vibrating plate used in a speaker apparatus,
generally, the higher the rigidity, the higher fh (high-path limit
frequency) can be set, which is advantageous when sound is
reproduced up to a high frequency band in a state of small
distortion.
[0005] Hence, various vibrating plates using metal materials of
aluminum, titanium and the like have been developed.
[0006] However, according to the metals, since an internal loss
(tangent.delta.) is small, when fh is produced in an audible band
up to 20 Hz through 20 KHz, in comparison with a resin species
vibrating plate whose major component is a resin material of, for
example, polyimide or the like, peak or dip significantly emerges
at a high frequency band to bring about a sound quality conversely
having large distortion.
[0007] Further, a specific weight of a metal material of aluminum,
titanium or the like is larger than that of a resin material and
therefore, there poses a problem that an efficiency of converting
an input signal into an output sound pressure is lowered.
[0008] From such a background, attention has been attracted to a
magnesium vibrating plate whose major component is magnesium more
light-weighted than aluminum or titanium and capable of achieving a
rigidity higher than that of a resin material as a metal species
vibrating plate excellent in high-path reproduction (refer to, for
example, JP-A-2002-369284).
[0009] Further, an explanation will be given of a structure of
fixing a vibrating plate of a speaker apparatus of a general cone
type to a frame in reference to FIG. 1 as follows.
[0010] FIG. 1 shows an example of bonding an edge 3 comprising a
resin to an outer periphery of a vibrating plate 1.
[0011] The vibrating plate 1 shown in FIG. 1 is of a cone type. The
edge 3 comprising the resin is constituted by a structure of
extending flange portions 3b, 3c to respectives of an inner
periphery and an outer periphery of a loop portion 3a for
permitting to displace the vibrating plate 1, generally, bonded to
the vibrating plate 1 by adhering the flange portion 3b
constituting an inner peripheral edge to an outer peripheral edge
of the vibrating plate 1 pertinently by an adhering agent. The
flange portion 3c constituting the outer peripheral edge of the
edge 3 is fixed to the flame of the speaker apparatus.
SUMMARY OF THE INVENTION
[0012] In the case of using a magnesium vibrating plate by the
vibrating plate of the cone type as shown by FIG. 1, when the edge
3 comprising a resin is bonded to the vibrating plate 1 by an
adhering agent, after processing to adhere the edge 3, a volatile
organic compound (VOC) of toluene or the like included in the
adhering agent is evaporated and there is a concern of effecting an
influence on an operator or contaminating environment.
[0013] Further, magnesium is liable to produce rust by being
brought into contact with air and therefore, there is executed rust
proofing for covering a surface of a thin film of magnesium
constituting the material of the magnesium vibrating plate by a
plated layer or an oxide film or the like.
[0014] Further, although an outer peripheral edge of the magnesium
vibrating plate is cut to a predetermined dimension after having
been formed in a predetermined cone shape, also a cut face of the
outer periphery needs to be subjected to an end face processing
with an object of rust proofing before adhering the edge 3
comprising a resin.
[0015] That is, when the magnesium vibrating plate has been
finished to form in the predetermined cone shape and is prepared to
the final dimension by cutting the outer peripheral edge, the cut
face of the outer periphery needs to be subjected to the end face
processing for rust proofing by bringing back the magnesium
vibrating plate to a surface treatment step or the like again, even
when the magnesium vibrating plate is prepared to the final
dimension, the magnesium vibrating plate cannot be shifted to a
step of bonding the edge and therefore, there poses a problem that
productivity is poor.
[0016] As problems to be resolved by the invention, there are
pointed out a problem caused in the above, that is, the problem
that the volatile organic compound is evaporated and the problem
that the magnesium vibrating plate cannot be shifted immediately to
the step of bonding the edge even when the magnesium vibrating
plate is prepared to the final dimension since the cut face of the
outer periphery needs to be subjected to the end face processing
for rust proofing and the productivity is poor, respectively as
examples.
[0017] According to a first aspect of the invention, a vibrating
plate for a speaker, includes: a magnesium vibrating plate whose
major component is magnesium; and an edge comprising a resin in
which an inner peripheral edge of the edge is bonded to an outer
peripheral edge of the magnesium vibrating plate for attaching the
magnesium vibrating plate to a frame, in which the inner peripheral
edge of the edge is constituted by a structure having a pinching
groove which the outer peripheral edge of the magnesium vibrating
plate is brought into close contact with and fitted to, and the
edge is formed integrally with the magnesium vibrating plate by
insert molding.
[0018] According to a second aspect of the invention, a method for
fabricating a vibrating plate for a speaker including a magnesium
vibrating plate whose major component is magnesium; and an edge
comprising a resin in which an inner peripheral edge of the edge is
bonded to an outer peripheral edge of the magnesium vibrating plate
for attaching the magnesium vibrating plate to a frame, includes:
forming the edge integrally with the magnesium vibrating plate by
insert molding, in which the inner peripheral edge of the edge is
constituted by a structure having a pinching groove which the outer
peripheral edge of the magnesium vibrating plate is brought into
close contact with and fitted to.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a vertical sectional view for explaining a
structure of fixing a vibrating plate in a speaker apparatus of a
general cone type to a frame.
[0020] FIG. 2 is a vertical sectional view for explaining a first
embodiment of the speaker apparatus using a vibrating plate for a
speaker according to the invention.
[0021] FIG. 3 is an explanatory view of a method of fabricating the
vibrating plate for a speaker shown in FIG. 2.
[0022] FIG. 4 is a vertical sectional view of other embodiment of a
speaker apparatus using a vibrating plate for a speaker according
to the invention.
[0023] FIG. 5 is an explanatory view of a method of fabricating the
vibrating plate for a speaker shown in FIG. 4.
DETAILED DESCRIPTION OF THE PREFFERED EMBODIMETNS
[0024] A detailed explanation will be given of embodiments of a
vibrating plate for a speaker and a method of fabricating the same
in reference to the drawings as follows.
First Embodiment
[0025] FIG. 2 is a vertical sectional view of a speaker apparatus
using a vibrating plate for a speaker of a first embodiment
according to the invention, and FIG. 3 shows a method of
fabricating the vibrating plate for a speaker shown in FIG. 2.
[0026] A speaker apparatus 11 shown in FIG. 2 is provided with a
vibrating plate 14 for a speaker bonding an edge 13 comprising a
resin to an outer periphery of a magnesium vibrating plate 12 of a
cone type, a voice coil bobbin 15 in a cylindrical shape connected
to an inner peripheral edge of the vibrating plate 12, a voice coil
16 wound around an outer periphery of the voice coil bobbin 15, a
magnetic circuit 18 formed with a magnetic gap 17 for containing
the voice coil 16, and a flame 19 for supporting the magnetic
circuit 18 and the vibrating plate 14.
[0027] According to the edge 13, an inner peripheral edge 13b
extended to an inner diameter portion of a loop portion 13a
constituting a damper for permitting an amplitude of the magnesium
vibrating plate 12 constitutes a portion of bonding to an outer
peripheral edge of the magnesium vibrating plate 12, and an outer
peripheral edge 13c extended to a side of an outer diameter of the
loop portion 13a is fixed to an edge supporting portion 19a of the
flame 19.
[0028] The inner peripheral edge 13b of the edge 13 is constituted
by a structure having a pinching groove 13d which the outer
peripheral edge of the magnesium vibrating plate 12 is brought into
close contact with and fitted to.
[0029] The edge 13 is molded in a predetermined shape by injection
molding of a resin and at that occasion, as shown by FIG. 3, the
edge 13 is formed integrally with the magnesium vibrating plate 12
by insert molding of constituting a state of holding the outer
peripheral edge 12a of the magnesium vibrating plate 12 which has
been cut to a predetermined dimension into a cavity 24 formed by
upper and lower dies 21, 22 for molding the edge and injecting the
resin into the cavity 24.
[0030] Notation 25 of FIG. 3 designates a runner (resin introducing
port for guiding the resin into the cavity 24.
[0031] In the case of the embodiment, the magnesium vibrating plate
12 is delivered to a resin molding step of executing inert molding
of the edge 13 after cutting the outer periphery to a predetermined
dimension in a state of not subjecting a cut face of the outer
periphery to an end face processing for rust proofing.
[0032] As a supplemental explanation, the magnesium vibrating plate
12 is formed with an anodized film dyed by a dyestuff at a surface
thereof to promote rust proofing of magnesium and design
performance after forming, for example, a magnesium thin plate as
major component is magnesium into a predetermined cone shape.
[0033] The anodized film may be formed by anodizing by using an
alkali mixed aqueous solution having pH equal to or lager than 12
including a metal salt and a thickness dimension thereof may be
constituted to be equal to or larger than 0.1 .mu.m and equal to or
smaller than 3 .mu.m.
[0034] An electrochemical deposition coating film may be provided
on a surface of anodized film. The electrochemical deposition
coating film is formed by using an electrochemical deposition
coating whose major component is an acrylic species resin. A
thickness dimension of the electrochemical deposition coating film
may be set to be equal to or lager than 2 .mu.m and equal to or
smaller than 30 .mu.m. By providing the electrochemical deposition
coating film, color tone of the surface of the magnesium vibrating
plate 12 can be finished by arbitrary color tone.
[0035] The magnesium thin plate constituting a raw material of the
magnesium vibrating plate 12 may be formed to a final thickness
(desired thickness) of 30 .mu.m through 100 .mu.m by repeating a
processing of rolling a base material whose major component is
magnesium in a heated state by a pertinent number of times.
[0036] The magnetic circuit 18 is constructed by a constitution
having a center pole 18a in a shape of a circular column arranged
at a back portion on a center axis of the magnesium vibrating plate
12, a first plate 18b formed by expanding an outer periphery of a
base end of the center pole 18a in a flange-like shape, a magnet
18c in a ring-like shape arranged on the first plate 18b, and a
second plate 18d in a ring-like shape covered on the magnet 18c to
be opposed to the first plate 18b, and a gap between an inner
peripheral face of the second plate 18d and an outer peripheral
face of the center pole 18a constitutes a magnetic gap 17 for
containing the voice coil 16.
[0037] The above-described magnetic circuit 18 forms a magnetic
circuit of an external magnet type for concentrating a magnetic
flux to the magnetic gap 17 and drives the voice coil 16 in a
direction of a center axis shown by an arrow mark A in accordance
with an electric signal inputted to the voice coil 16.
[0038] According to the vibrating plate 14 for a speaker and the
method of fabricating the same explained as described above,
bonding of the edge 13 comprising the resin to the outer peripheral
edge of the magnesium vibrating plate 12 is realized by insert
molding and an adhering agent is not used.
[0039] Therefore, there is not brought about a situation of
evaporating a volatile organic compound in an adhering agent and an
influence on an operator and contamination of an environment caused
by evaporating the volatile organic compound can be prevented.
[0040] The inner peripheral edge 13b of the edge 13 bonded to the
outer peripheral edge of the magnesium vibrating plate 12 by insert
molding is constituted by a structure having the pinching groove
13d which the outer peripheral edge of the magnesium vibrating
plate 12 is brought into close contact with and fitted to and the
cut face of the outer periphery of the magnesium vibrating plate 12
is covered by the pinching groove 13d to prevent from being brought
into contact with outer air for generating rust at the cut
face.
[0041] Therefore, as described above, even when the edge 13 is
bonded to the cut face of the outer periphery of the magnesium
vibrating plate 12 by dispensing with an end face treatment for
rust proofing, rust can be prevented from being produced.
[0042] That is, when the magnesium vibrating plate 12 is prepared
to a final dimension by cutting the outer periphery or the like, by
dispensing with the end face treatment for rust proofing, the
magnesium vibrating plate 12 can immediately be shifted to a step
of bonding the edge 13 (insert molding step) and productivity can
be promoted by reducing operating steps.
[0043] In the vibrating plate for a speaker and the method of
fabricating the same according to the invention, a structure of the
magnesium vibrating plate is not limited to the cone type shown in
the first embodiment but can also be constituted by, for example, a
dome type as shown by a second embodiment described below.
Second Embodiment
[0044] FIG. 4 is a vertical sectional view of a speaker apparatus
using a vibrating plate for a speaker of a second embodiment
according to the invention, and FIG. 5 shows a state of forming an
edge of the vibrating plate for a speaker shown in FIG. 4 by insert
molding.
[0045] A speaker apparatus 31 shown in FIG. 4 is provided with a
vibrating plate 34 for a speaker bonding an edge 33 comprising
resin thereof to an outer periphery of a magnesium vibrating plate
32 of a dome type, the voice coil bobbin 15 in the cylindrical
shape connected to an outer peripheral edge of the magnesium
vibrating plate 32, the voice coil 16 wound around the outer
periphery of the voice coil bobbin 15, the magnetic circuit 18
formed with the magnetic gap 17 for containing the voice coil 16,
and the frame 19 for supporting the magnetic circuit 18 and the
vibrating plate 32.
[0046] According to the edge 33, an inner peripheral edge 33b
extended to an inner diameter portion of a loop portion 33a
constituting a damper for permitting an amplitude of the magnesium
vibrating plate 32 constitutes a portion of bonding to an outer
peripheral edge of the magnesium vibrating plate 32, and an outer
peripheral edge 33c extended to an outer diameter side of the loop
portion 33a is fixed to the edge supporting portion 19a of the
frame 19.
[0047] A structure in which the inner peripheral edge 33b of the
edge 33 is provided with a pinching groove 33d which is the outer
peripheral edge of the magnesium vibrating plate 32 is brought into
close contact with and fitted to is common to that of the case of
the above-described embodiment of the cone type.
[0048] The edge 33 is molded at a predetermined shape by injection
molding of a resin and in that occasion, as shown by FIG. 5, the
edge 33 is formed integrally with the magnesium vibrating plate 32
by insert molding of constituting a state of holding the outer
peripheral edge 32a of the magnesium vibrating plate 32 which has
been cut to a predetermined dimension into a cavity 44 formed by up
and lower dies 41, 42 for molding the edge and injecting the resin
into the cavity 24.
[0049] Notation 45 of FIG. 5 designates a runner (resin introducing
port) for guiding the resin into the cavity 24.
[0050] Also in the case of the second embodiment, the magnesium
vibrating plate 32 is delivered to a resin molding step of
executing insert molding of the edge 33 for integral molding with
the edge 33 in a state in which a cut face of an outer periphery
thereof is not subjected to an end face treatment for rust proofing
after cutting the outer periphery to a predetermined dimension.
[0051] According to the magnesium vibrating plate 32, a method of
fabricating a magnesium thin plate constituting a raw material and
a fabricating condition, a surface treatment of forming an anodized
film formed at a surface of the magnesium thin plate for promoting
rust proofing of magnesium and design performance may be common to
those in the case of the above-described first embodiment and an
explanation thereof will be omitted according to the
embodiment.
[0052] As described above, even when the magnesium vibrating plate
32 is of the dome type, by integrally forming the edge 33 to the
magnesium vibrating plate 32 by insert molding shown in FIG. 5 in
the structure having the pinching groove 33d which the inner
peripheral edge 33b of the edge 33 for bonding with the outer
peripheral edge of the magnesium vibrating plate 32 is brought into
close contact with and fitted to the outer peripheral edge 32a of
the magnesium vibrating plate 32, operation and effect similar to
those of the first embodiment can be achieved.
[0053] That is, since an adhering agent is not used for bonding the
edge 33 to the magnesium vibrating plate 32, there is not brought
about a situation of evaporating a volatile organic compound in an
adhering agent and influence on an operator and contamination of an
environment caused by evaporating a volatile organic compound can
be prevented.
[0054] When the magnesium vibrating plate 32 is prepared to a final
dimension by cutting the outer periphery or the like, by dispensing
with an end face treatment for rust proofing, the magnesium
vibrating plate 32 can be shifted to a step of bonding the edge 33
(insert molding step) and productivity can be promoted by reducing
operating steps.
* * * * *